Over the past several decades, several advances have been made in the field of endoscopy, and in particular relating to the breaking up of physiologic calculi in the bile ducts, urinary tract, kidneys, and gall bladder. Physiological calculi in these regions may block ducts and cause a patient a substantial amount of pain and therefore must be broken down and/or removed. Different techniques have been developed to break up stones, including ultrasonic lithotripsy, pneumatic lithotripsy, electro-hydraulic lithotripsy (EHL), and dissolution of calculi using YAG or holmium lasers, for example.
A number of rigid solid or tubular probe-based lithotripsy devices that use ultrasonic or pneumatic energy to break the stone into smaller pieces for easier removal from the patient's urologic system have been developed. For example, the Olympus LUS-2, the Gyrus ACMI Cyberwand, and the Swiss Lithoclast are such devices. They may function by having ultrasonic or acoustic frequency energy transmitted down a stiff metal probe and delivered by contact to a kidney stone. Ultrasonic lithotripters generally require tuned probes and the effectiveness of these lithotripters depend on their ability to maintain resonance down the length of the probe (i.e. ultrasonic energy does not travel well around bends or turns). It is believed that probe bending can dissipate enough heat to seriously damage adjacent tissue or the endoscopic device itself, in addition to the loss of energy transfer to the tip of the probe.
For procedures performed with a tubular probe device, suction of liquid and debris during the lithotripsy procedure may be possible via the center of the tubular probe. Some devices may incorporate and deliver a lower frequency energy component to the kidney stone either through the same probe or via a second probe; this second probe is usually coaxial to the ultrasonic energy probe (i.e. the Cyberwand). This secondary, lower frequency energy shows evidence of improving the stone breaking efficiency over a solely ultrasonic energy approach.
Throughout the procedure, bodily waste including blood, stone debris, fluids and/or tissue have been removed from the patient through active suction and have passed through the lithotripsy probe and a central lumen of the handpiece. Most lithotripters include interchangeable probes that are added and removed from the lithotripter depending on the particular need for a particular procedure. The probe may be removed from sterile packaging, removed from non-sterile packaging and subsequently sterilized, or sterilized and reused from a previous procedure, and connected to the handpiece after the surgical handpiece has been sterilized. After a procedure is performed, the one or more probes are typically removed from connection at a distal end of a handpiece and may be discarded or sterilized for reuse in a subsequent procedure. The handpiece, including the internal lumen which may still contain bodily waste is subsequently processed for sterilization. Sterilization procedures that might occur on a lithotripsy device include wet/steam sterilization, dry heat sterilization, ethylene oxide, or sporicidal chemicals, for example.
In the case of an ultrasonic lithotripsy device, the evacuation path of the waste liquid is commonly through the center of the driver. If the ultrasonic driver is massive enough and the lumen is small enough, and the preferred sterilization method is autoclaving, it may be difficult to achieve a high enough temperature in the center of the ultrasonic driver to sufficiently sterilize the full length of the central lumen.
A potential result of bodily waste remaining in the central lumen of the handpiece or perhaps being rinsed out quickly before entering the sterilizer is that complete sterilization of the device with a four minute flash cycle, for example, may not be possible. However, in certain situations when fast sterilization is needed, this type of sterilization procedure may be run without fully sterilizing the device.
It is contemplated that there is a need for a lithotripter that allows for reliably eliminating a bulk of bodily waste to facilitate rapid sterilization cycles. This can result in practitioner and patient confidence that a complete sterilization has been achieved before reusing the device on a subsequent procedure.